K-278 Komsomolets

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K-278 Komsomolets
K-278
K-278
Ship data
flag Soviet UnionSoviet Union (naval war flag) Soviet Union
Ship type Nuclear submarine
Shipyard Shipyard 402 , Severodvinsk
Build number 510
Keel laying April 22, 1978
Launch May 9, 1983
Whereabouts sunk on April 7, 1989
Ship dimensions and crew
length
110 m ( Lüa )
width 12.3 m
Draft Max. 9.5 m
displacement surfaced: 5,880 t

submerged: 8,500 t

 
crew 64 men
Machine system
machine 1 × pressurized water reactor OK-650 b-3
Machine
performance 		190 MW th
propeller 1
Mission data submarine
Diving depth, normal 1,000 m
Immersion depth, max. 1,250 m
Top
speed
submerged 		30 kn (56 km / h)
Top
speed
surfaced 		14 kn (26 km / h)
Armament

Ammunition:

Sensors

"Snoop Head" surface search radar,
active low-frequency sonar "Shark Gill"
system for electronic warfare "Bald Eagle"

The K-278 Komsomolets was a Soviet nuclear submarine . It entered service in 1984 and sank on April 7, 1989. The sinking cost the lives of 42 crew members.

Project 685 Plawnik

The project, known as Plawnik ( Russian Плавник for Finn ; NATO code name Mike ), was an advanced submarine design that was launched to test new technologies. The prototype boat K-278 Komsomolets remained the only boat of this class.

The boat should be armed with a variety of torpedoes and anti-submarine missiles. The anti-submarine missiles could be armed with both conventional and nuclear warheads. Development work began in the 1960s. The keel laying of the first boat took place on April 22, 1978.

Komsomolets

This boat was named Komsomolez (Russian Комсомолец for member of the Komsomol ). The boat, hull number K-278, was launched on May 9, 1983 and put into service at the end of 1984. A second unit was laid down in Severodvinsk , but canceled before completion.

The boat was built according to the usual requirements of the Soviet Navy . It was a two-hull boat with seven partitioned off compartments (from front to stern):

The inner pressure hull was made of titanium , which gave the boat the greatest diving depth of all submarines available at the time. The boat was able to operate at a depth of 1000 m. This depth could not be reached by the best US submarine available at the time. At the same time, due to the titanium hull , the boat was very difficult to locate with MAD sensors . The Mike class had an escape capsule integrated into the tower structure , which the crew was supposed to carry to the surface in an emergency. Western secret services suspected two lead-bismuth - cooled reactors similar to Project 705 . The Soviet Union stated that the boat would be powered by a single pressurized water reactor of conventional design. A direct consequence of this was the significant decrease in the estimated speed of the boat. If you initially assumed up to 38 kts in the submerged state, it was corrected down to less than 30 kts.

A direct disadvantage of the very special liquid metal-cooled reactors that may be used is the need to keep the reactor pressure vessel at operating temperature at all times. Without a constant supply of heat, the liquid metal solidifies and the reactor cannot be started up. In order to shut down the reactor completely (0% power), an external supply of hot steam must be ensured in order to keep the metal in a liquid state.

The fate of the Komsomolets

On April 7, 1989, a fire broke out in the rear of the Komsomolets . The boat was at a depth of 150 to 380 meters when a valve on a high pressure air line connecting the boat's main ballast tanks burst and leaking oil (presumably from the hydraulic valve) caught fire on a hot surface. The spread of the fire could not be stopped by sealing off the departments as the fire spread through the boat's cable ducts. As a direct consequence, the automatic emergency shutdown of the reactor was initiated to prevent overloading. This caused the drive to fail. The lack of power resulted in system failures throughout the boat, including failure of most of the safety systems. The boat managed to surface after eleven minutes, but the crack in the compressed air system fueled the fire. Most of the crew left the boat. After a few hours the hull broke and the boat sank. The commander and four other crew members who remained on board tried to save themselves with the emergency capsule. However, this was partially flooded and filled with toxic gases - only one of them survived the ascent to the surface. The crew had called for help and there were rescue planes on site to drop life rafts when the emergency exit from the boat occurred, but there weren't enough for the 50 men. Of the 69 crew members, 42 died during and after the accident, most of them from hypothermia in the cold water, as they did not manage to put on their rescue suits before the emergency exit.

The boat is located around 190 km west-southwest of Bear Island in the Northern European Sea off the coast of Norway at a depth of around 1858 meters at position 73 ° 43 ′ 17 ″  N , 13 ° 15 ′ 51 ″  E Coordinates: 73 ° 43 ′ 17 ″  N , 13 ° 15 '51 "  O .

At the time of the sinking, the boat was carrying two nuclear and eight conventional torpedoes. Two investigations were initiated, one by the government of the USSR and the other later by an independent body. Both could not fully clarify the exact circumstances that led to the loss of the boat; the second investigation, however, saw the cause of the boat's construction deficiencies. The poor level of training of the crew was also criticized. Norway later stated that the boat could have been reached by air or sea two hours before the sinking, but that they were notified too late.

The consequences of the sinking of the Komsomolets

The sinking site is in one of the richest areas in fish in the world, and a leak from the radioactive inventory could cost the fishing industry billions in losses. In May 1992 the research ship Akademik Mstislaw Keldysch was ordered to the scene of the accident and discovered numerous fractures along the entire length of the titanium pressure hull. Some were up to 40 cm long. In addition, it was believed that cracks in the primary cooling circuit could be recognized. Cracks in this cycle would allow radioactive material to leave the reactor core and get into the seawater and thus into the food chain. In the spring of 1993, the Russian government classified the breaks as harmless. Another study in August 1993 examined the circulation movements of the water at the accident site, but found no “vertical mixing” of the layers and thus no acute risk of radioactive contamination. However, one was amazed at a nearly 8 m large hole in the bow torpedo room, which could not be explained with the cause of the accident, but which clearly resulted from an explosion.

During dives with miniature submarines, it was found that the seawater has started to decompose the jackets of the torpedo warheads and the hull of the boat. This process is accelerated by the rapidly changing currents of the water in the area. If radioactive material were to escape under these conditions, rapid spread would be inevitable. When in the summer of 1994 an investigation found that plutonium-239 was leaking from one of the warheads, the torpedo shaft was sealed.

The cost of salvaging the boat in 1995 was estimated at over a billion US dollars. It also carried the risk that the shell could break during the project. As an alternative plan, sealing the boat with a jelly-like material was considered. Implementation of this plan began on June 24, 1995 and was completed in July 1996. The case is assumed to provide 20 to 30 years of protection.

Norwegian investigations in 2008 found no significant radioactivity in the wreck of the K-278.

Spread over July 8 and 9, 2019, a Norwegian-Russian team took targeted water samples from a pipe that Russian expeditions identified as a radioactivity leak in the 1990s and 2007, and from a few meters above. The cesium -137 activity in the six samples from the tube ranged from less than 10  Bq / l ( detection limit on board) to 100 (on the 8th) or 800 Bq / l (on July 9th) in the vicinity no activity can be detected. More sensitive measurements on land continue). The very low cesium-137 background activity in these waters is around 0.001 Bq / l. Since the small amounts that leak out quickly dilute, there is no risk to fish stocks or the population. The Norwegian limit value in food is 600 Bq / kg.

criticism

Many details of the sinking are still unclear, but it is assumed that the construction was incorrect. It is therefore incomprehensible that the crew did not succeed in emptying the compressed air system in order to deprive the sources of the fire of oxygen. The failure of the safety systems, the spread of the fires through the cable ducts and the failure of the main reactor are further inconsistencies.

In addition, the shell of the Komsomolez has not proven to be corrosion-proof. The flooding of the escape pod with water, its filling with toxic gases, the failure of the fire extinguishing systems, the ignition of the oil on a hot surface and the failure of the crew to fight the fire indicate a faulty design.

See also

literature

  • Alexander Antonov, Walerie Marinin, Nikolai Walujew: Soviet-Russian nuclear submarines. Berlin 1998.
  • С. А. Спирихин: Надводные корабли, суда и подводные лодки постройки завода №402. (For example: SA Spirichin: Surface ships, vehicles and submarines built at shipyard No. 402. ) Arkhangelsk 2004, ISBN 5-85879-155-7 (Russian).

Web links

Commons : K-278  - Collection of pictures, videos and audio files

Footnotes, sources

  1. ↑ a b http://www.atrinaflot.narod.ru/1_submarines/03_pla_685/0_685.htm ( Memento from October 17, 2007 in the Internet Archive ) atrinaflot.narod.ru, Russian, viewed on November 12, 2008
  2. ↑ [1] George Montgomery, CIA, unfortunately, sighted November 12, 2008
  3. ↑ [2] Investigations into the accident, Russian, viewed November 12, 2008
  4. ↑ TED Case Studies ( Memento from October 29, 2015 in the Internet Archive ) (English)
  5. ^ Peter Lobner: Marine Nuclear Power 1939-2018. 2018. p. 128.
  6. ↑ Hilde Elise Heldal, Stine Hommedal: Researchers discovered leak from Komsomolets. Institute of Marine Research, July 10, 2019, updates on July 11. and 29 August 2019, as well as personal communication on 29 August 2019.